The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Multi-mode powertrain systems employ internal combustion engines and non-combustion torque machines to generate driveline torque in response to an output torque command from an operator, taking into account fuel consumption, power consumption, torque management, auxiliary power demands, emissions, driveability, and other factors.
Exhaust aftertreatment systems are employed on internal combustion engines to treat engine exhaust emissions including HC, CO, NOx, particulate matter, and other gas constituents. This includes devices that are configured to oxidize, reduce, reform, filter, and otherwise transform exhaust gas constituents to elemental nitrogen, carbon, CO2, H2O, and other molecules in the presence of catalysts and other constituents.
Exhaust aftertreatment devices include catalysts that are configured to perform one or more of the aforementioned processes on constituents in the exhaust gas feedstream. Known catalysts are characterized in terms of gas conversion rate in relation to operating temperature of the catalyst. Catalyst light-off temperature, which refers to a temperature at which the catalyst has a conversion rate of 50%. The catalyst light-off temperature correlates to operation of the catalyst which is exothermic in nature, and is thus self-sustaining without need for additional engine control operation to introduce heat into the catalyst.